Duloxetine for Multiple Sclerosis Pain

Duloxetine in Patients With Central Neuropathic Pain Due to Multiple Sclerosis.

This study is designed to primarily assess the efficacy and safety of duloxetine 60-120 mg once daily (QD) compared with placebo on the reduction of pain severity in participants with central neuropathic pain due to Multiple Sclerosis.

Study is a multicenter, randomized, double-blind, parallel, placebo-controlled, 20-week trial with 4 study periods. Participants who screen successfully (Study Period I) will be randomized in a 1:1 fashion to duloxetine 60 mg QD or placebo. Starting with Study Period II, participants will be treated in a double-blind manner for 6 weeks. Participants who complete the 6-week, double-blind period will have the opportunity to participate in a 12-week, open-label, flexible-dose portion of the study (Study Period III). Study Period IV is a taper phase designed to reduce the occurrence of discontinuation adverse events. Participants may enter Study Period IV at any time after Visit 3.

Inclusion Criteria:

• Have central neuropathic pain due to multiple sclerosis (MS) based on the disease diagnostic criteria

• Adult males or females

• Have a score of 4 or greater on the daily 24-hour average pain score

• Females must test negative for pregnancy at study entry

• Complete the daily diaries for at least 70% of the days of the study

• Participants may continue other prescription and nonprescription analgesic pain medications as long as the dose has been stable for 1 month prior to study entry, and they agree to maintain that stable dose throughout the study Disease Diagnostic Criteria:

  • Diagnosis of MS at least 1 year prior to study entry
  • No MS flares or change in disease treatment for the 3 months prior to study entry
  • Daily pain due to MS for a minimum of 3 months prior to study entry

Exclusion Criteria:

• Are currently in a clinical trial of MS disease-modifying therapy
• Have pain that cannot be clearly differentiated from causes other than MS
• Any current or historical diagnosis of mania, bipolar disorder, psychosis, or schizoaffective disorder
• History of substance abuse or dependence
• Are pregnant or breast-feeding